Rock drill rotation means



1937. E. G. GARTIN 2,100,324

ROCK DRILL ROTATION MEANS Filed April 26, 1934 (79 gut Q} a? 46 Patented Nov. 3%, 1937 STATES PATENT QFFEQE RQCK DRILL ROTATION MEANS Massachusetts Application April 26, 1934, Serial No. 722,571

14.- Claims.

This invention relates to rock drills, and more particularly to improvements in the drill steel rotation means of such drills.

An object of this invention is to provide an im- 5 proved rock drill rotation mechanism. A further object is to provide an improved rock drill having improved fluid distribution means and having associated therewith improved rotation means controlled by said distribution means. Yet another object is to provide an improved drill steel rotation mechanism of the independent motor controlled type whereby the drill steel may be rotated independently of the reciprocatory movement of the hammer motor piston. other object is to provide an improved independent motor controlled type rotation mechanism controlled automatically by the fluid distributing valve whereby the rotation control motor is intermittently operated. A further object is to provide an improved drill steel rotation mechanism of the type wherein a rifle bar cooperates with a rifle nut secured within the hammer piston and having associated therewith improved means for regulating rifle bar rotation whereby the drill steel is intermittently rotated in an improved manner. A still further object is to provide an improved rotation control means controlled by the fluid distributing valve for regulating rotation of the rifle bar and for holding the rifle bar against rotative movement. These and other objects and advantages of the invention will, however, hereinafter more fully appear.

In the accompanying drawing there is shown a for purposes of illustration one form which the 35 invention may assume in practice. 7

In this drawing,

Fig. 1 is a central, longitudinally extending, vertical sectional view taken through the improved rock drill showing one illustrated form 40 of the improved drill steel rotation means.

2 is a view similar to Fig. 1 showing the hammer motor parts in a different position.

Fig. 3 is a cross sectional view taken on line 33 of Fig. 1.

Fig. 4 is a cross sectional view taken on line 4-4 of Fig. 1.

In this illustrative embodiment of the invention there is shown a rock drill of the pressure fluid actuated, hammer type comprising a motor cylinder I having a bore 2 containing a reciprocable hammer piston 3. This hammer piston has a forwardly projecting cylindrical striking bar 4 extending through a bore 5 formed in the front motor head 6 and adapted to deliver a series of impact blows to the shank I of a usual hollow Still an- 7 drill steel. This drill steel is mounted in the usual manner in a chuck bushing 8 secured within a rotatable chuck sleeve 9 journaled within a front chuck housing I0. The rear end of the cylinder bore is closed by a rear head I I held in position by a rear head block I2 and this rear head I I is formed with an axial recess I3 adapted to receive a cylindrical projection 14 extending rearwardly from the piston head in the manner shown in Fig. 1. The cylinder I, front head 6, chuck housing I and the rear head I I and head block I2 are held in assembled relation by usual side bolts I5, I as shown in Fig. 4. Arranged in a transverse bore I6 formed in a boss projecting laterally from the side of the motor cylinder is a control valve II for supplying pressure fluid from any suitable source, through a central chamber I8 and lateral port I9 in the valve to a passage 20 leading to an annular groove 2I formed in the cylinder. This groove 2| communicates with an annular valve chamber 22 formed in the rear head and cylinder, and this chamber communicates at its forward side through an annular opening directly with the rear end of the cylinder bore. The rear wall of the Valve chamber 22 has formed therein a recess 23 communicating with the inlet of the independent rotation control motor, as hereinafter described, and through a passage 2 with the forward end of the cylinder bore. Also formed in the rear wall of this valve chamber is an arcuate groove 25 to which pressure fluid is constantly supplied through a groove 26 communicating with the fluid supply passage 20. The cylinder is provided with a centrally located, piston controlled, free exhaust passage 2?. Reciprocable on the cylindrical guide portion 28 of the rear head II is a fluid distributing valve 29 of the annular flat disc type for controlling the supply of pressure fluid to the recess 23 and to the rear end of the cylinder. This valve is thrown in the rearward direction by compression pressure built up by the piston within the rear end of the cylinder bore during the retractive piston stroke, and is thrown in the opposite direction by constant pressure in the groove 25 acting against the opposed piston controlled reduced pressure. As the particular motor structure disclosed is of a well known design, further detailed description with suitable shafts 39 journaled Within the rear head ll and head block l2 in the manner shown in Fig. 1. In this instance, the central rotor 37 is preferably formed integral with a rifle bar 3% suitably journaled within the rear head and head block and having spirally arranged grooves 16 interlocked with spiral vanes 4| formed on a rifle nut 32 secured within the rear end of the hammer piston. The piston striking bar l is provided with longitudinal flutes .43 interlocked with straight vanes 44 formed on the rotatable chuck sleeve 9. In this illustrative construction, fluid supply passages 45 and 46 lead from the recess 23 to the inlet sides of the motor rotors, the motor chamher at the exhaust sides of these rotors being connected to exhaust through exhaust passages il and 48.

The operation of the rock drilling motor will be clearly apparent from the description given. When the distributing valve 29 is in the position shown in Fig. 1, pressure fluid may flow from the chamber is through port i9, passage 26, annular groove 2i through the valve chamber past the forward surface of the valve directly to the rear end of the cylinder bore, the pressure fluid acting on the rear pressure area of the hammer piston to drive the latter forwardly to effect its working stroke. Upon the initiation of the forward piston stroke the front end of the cylinder bore is connected to exhaust through the free exhaust passage 2'! and the communication of the recess 23 and passage 2G with the supply groove 2! is out off by the valve 29. As the rear edge of the piston head overruns the exhaust passage 21 the pressure within the rear end of the cylinder bore is substantially reduced, and as a result the distributing valve is thrown from its position shown in Fig. 1 forwardly to its position shown in Fig. 2 by the constant pressure in groove 25 acting on the rear pressure area of the valve. Pressure fluid then flows from the chamber l8 in the valve through port l9, passage 29, supply groove 2! recess 23 and passage 24 to the forward end of the cylinder bore, the pressure fluid acting on the forward pressure area of the piston to drive the latter rearwardly to effect its retraction stroke. Upon the initiation of rearward piston movement the rear end of the cylinder bore is connected to exhaust by the exhaust passage 21. When the piston head overruns the exhaust passage 2'! pressure fluid is trapped within the rear end of the cylinder bore, and this fluid is highly compressed as the piston continues its rearward movement. This compression pressure acts on the front pres sure area of the distributing valve to throw the latter rearwardly from the position shown in Fig. 2 to the position shown in Fig. 1, these operations being rapidly repeated during normal operation of the hammer motor.

The drill steel rotation means operates in the following manner: When the distributing valve 29 is in the position shown in Fig. 2, pressure fluid flows past the valve through recess 23 and passages 45 and 35 to the rotation control motor inlet, and the motor rotors are at that time locked in stationary position by the pressure fluid within the motor inlet. As the hammer piston moves'rearwardly the vanes on the rifle nut 42 engage with the spiral grooves on the then stationary rifle bar, causing the hammer piston to be rotated, and this rotative movement of the piston is transmitted through the flutes 43 on the striking bar and the vanes M on the chuck sleeve to the drill steel. When the distributing valve 29 is thrown to the position shown in Fig. 1, pressure fluid in the recess 23 and passages 35 and 46 is connected to exhaust, thereby causing the motor rotors to revolve freely during the forward working stroke of the hammer piston so that the latter delivers an unimpeded impact blow to the drill steel shank. The rotors, in certain instances, may cooperate with the rifle bar in the rotating of the piston during the retractive piston stroke, particularly when the drill steel is relatively free to rotate due to decreased resistance of the steel the work. When the drill steel sticks, due to an abnormal resistance to drill steel rotation during the retractive piston stroke, the piston effects rotation of the rifle bar, causing the rotors turn backwards, the rotors at that displacing fluid as they rotate, and as a result acting as a fluid displacement pump. When the drill steel ispenetrating relatively soft material and is relatively free to rotate the rotors act as a motor in aiding in the rotation of the steel.

As a result of this invention, it will be noted that an improved rock drill is provided having improved means for rotating the drill steel. It will further be noted that an improved independent rotation control means is provided for the drill steel whereby the steel rotation is controlled by an independent rotation control motor controlled by the distributing valve of the hammer motor. These and other uses and advantages of the improved rotation means will be clearly apparent to those skilled in the art.

.While there is in this application specifically described one form which the invention may assume practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a rock drill, a pressure fluid actuated hammer motor comprising a cylinder and a piston reciprocable therein, said piston adapted to deliver impact blows to the shank of a drill steel, and drill steel rotation means comprising a rifle bar interlocked with the piston, a rotary lock for controlling rifle bar rotation and including a rotary locking element fixed to rifle bar, means for supplying pressure fluid to said rotary lock to lock said rotary locking element against rotation during the piston stroke in one direction and for connecting said lock to exhaust to release said rifle bar for free rotation during the other piston stroke, said rifle bar when held against rotation effecting rotation of the piston during one piston stroke, and means for transmitting the rotary drill steel. I

2. In a rock drill, a pressure fluidactuated hammer motor comprising a cylinder, a piston reciprocable therein, said piston adapted to deliver impact blows to the shank of a drill steel, and drill steel rotation means comprising a rifle bar having spirally arranged grooves interlocked with the hammer piston, and a rotary lock controlling rifle bar rotation and including a rotary locking element fixed to said rifle bar, and means for supplying pressure fluid to said rotary lock to lock said rotary locking element against rotation during the piston stroke in one direction and for connecting said lock to exhaust to release said rifle bar for free rotation during the other piston stroke.

3. In a rock drill, a cylinder, 2. piston reciprocable therein, said piston adapted to deliver immotion of the piston to the 7 pact blows to the shank of a drill steel, fluid distribution means for eflecting piston reciprocation including an automatic fluid distributing valve, and drill steel rotation means comprising a rotary lock having a. rotary locking element, connections bet, a piston and locking element whereby when r is locked the other rotates upon p reciprocation, means for transmitting the l tary motion of said piston to the drill steel and operative when the rotation of the drill steel is abnormally resisted by the work to lock the piston against rotation, and means controlled by said distributing valve for controlling said rotary lock to lock said locking element against rotation during one piston stroke and for effecting free release of said locking element during the opposite piston stroke.

4. In a rock drill, a cylinder, a piston reciprocable therein, said piston adapted to deliver impact blows to the shank of a drill steel, fluid distribution means for eflecting reciprocation of said piston, and means associated with said fluid distribution means for effecting drill steel rotation including a fluid operated rotation control lock of the rotary type having a rotary locking element, connections between said piston and said locking element whereby when either is locked the other rotates upon piston reciprocation, means for transmitting the rotary motion of the piston to the drill. steel and operative when the rotation of the drill steel s abnormally resisted by the work'to lock the piston against rotation, and means controlled by said fluid distribution means for supplying pressure fluid to said rotary lock to lock said rotary locking element during one stroke of the piston and for connecting said lock to exhaust to release said look ing element for free rotation during the other piston stroke.

5. In a rock drill, a cylinder, a piston reciprocable therein, said piston adapted to deliver impact blows to the shank of a. drill steel, fluid distribution means for eflecting reciprocation of said piston, means. associated with and controlled by said fluid distribution means for eifecting drill steel rotation including a rotation control lock of the rotary type havin a rotary locking element, and a spirally grooved rifle bar fixed to said rotary locking element and controlled by said lock, said locking element adapted to rotate freely with said rifle bar during one piston stroke, and means for inter ocking said rifle bar with the motor piston.

6. In a rock drill, a cylinder, a piston reciprocable therein, said piston adapted to deliver impact blows to the shank of a drill steel, fluid distribution means for effecting piston reciprocation including an automatic fluid distributing valve, and drill steel rotation means including a fluid operated control k of the rotary type for effecting drill steel rotation and having a rotary locking element, connections between said piston and locking element whereby when either is locked the other rotates upon piston reciprocation, means for transmitting the rotary motion of the piston to the d ill stee and operative when th rotation of the drill steel is abnormally resisted by the work to lock the piston against rotation, and passage means controlled by said distributing valve for supplying pressure fluid to said rotary lock to lock intermittently said rotary locking element against rotation.

'7. In a rock drill, cylinder, a piston reciprocable therein, said piston adapted to deliver impact blows to the shank of a drill steel, fluid distribution means for effecting piston reciprocation including an automatic fluid distributing valve, and drill steel rotation means including a fluid operated rotation control lock of the rotary type for effecting drill steel rotation and having a rotary locking element, passage means controlled by said distributing valve for supplying pressure fluid to said lock for locking said rotary locking element against rotation during one piston stroke and to eflect free release of said locking element during the opposite piston stroke, a rifle bar fixed to said rotary locking element and controlled by said lock, said rifle bar interlocked with the motor piston for effecting rotary motion of the piston during one piston stroke, and means for transmitting the rotary motion of the piston to the drill steel.

8. In a rock drill, a cylinder, a piston reciprocable therein for delivering impact blows to a drill steel, and drill steel rotation means comprising an interlocking connection between the piston and the drill steel for transmitting the rotary motion of the piston to the steel, a rifle bar having a spiral groove interlocking connection. with the piston for intermittently rotating the latter, intermeshing gears connected to the rifle bar. and means for supplying pressure fluid to said gears to lock the latter during one stroke of the piston and for exhausting said fluid to release gears and rifle bar for free rotation during the other piston stroke.

9. In a rock drill, a pressure fluid actuated hammer motor comprising cylinder, a piston reciprocable therein for delivering impact blows to drill steel, and fluid distribution means for effecting reciprocation of said piston, and drill steel rotation means comprising an interlocking connection between the piston and drill steel for transmitting a rotary motion of the piston to the steel, a rifle bar having a spiral groove interlocking connection with the piston for intermittently rotating the latter, intermeshing gears connected to the rifle bar, and means controlled by said fluid distribution means for supplying pressure fluid to said gears to lock the latter during one stroke of the piston and for exhausting said fluid to release said gears and rifle bar for free rotation during the other piston stroke,

10. In a rock drill, a pressure fluid actuated hammer motor comprising a cylinder, a piston reciprocable therein for delivering impact blows to a drill steel, and fluid distribution means for effecting reciprocation of said piston, and drill steel rotation means comprising an interlocking connection between the piston and drill steel for transmitting the rotary motion of the piston to the steel, a rotation bar having an interlocking connection with the piston for rotating the latter, an intermeshing gear type lock having a. locking gear fixed to the rotation bar, and means controlled by said fluid distribution means for supplying pressure fluid to said lock to lock the gears of the latter during one stroke of the piston and for exhausting said lock to release said rotation for free rotation during the other piston stroke.

11. In a rock drill, a pressure fluid actuated hammer motor comprising a cylinder, a piston reciprocabie therein for delivering impact blows to a drill steel, and fluid distribution means for eilecting reciprocation of said piston, and drill steel rotation means comprising an interlocking connection between the piston and drill steel for transmitting the rotary motion of the piston to the steel, a rotation bar having an interlocking connection with the piston for rotating the latter, a rotary motor having a rotary motor element fixed to the rotation bar, and means controlled by said fluid distribution means for supplying pressure fluid to said motor to lock the motor element of the latter during one stroke of the piston and for exhausting said motor to release said rotation bar for free rotation during the other piston stroke.

12. In a rock drill, a pressure fluid actuated hammer motor comprising a cylinder, a piston reciprocable therein for delivering impact blows to a drill steel, and fluid distribution means for effecting reciprocation of said piston, and drill steel rotation means comprising means connected to said piston for rotating the latter and for transmitting he rotary piston motion to the drill steel, an independent rotation motor operatively connected to said transmitting means, and means controlled by said fluid distribution means for supplying pressure fluid to said rotation motor to lock the latter against rotation during the piston stroke in one direction and for exhausting said motor to release the latter for free rotation during the piston stroke in the opposite direction, said rotation motor control means including means controlled by said fluid distribution means for supplying pressure fluid to said rotation motor to operate said transmitting means connected to said piston to aid the latter in the rotating of the drill steel.

13. In a rock drill, a cylinder, a piston reciprocable therein, said piston adapted to deliver impact blows to the shank of a drill steel, fluid distribution means for efiecting piston reciprocation including an automatic fluid distributing valve, and drill steel rotation means including a device alternatively operable as a pump or as a motor and having a rotary element, connections between said piston and said rotary element whereby when either is locked the other rotates upon piston reciprocation, means for transmitting the rotary motion of the piston to the drill steel and operative when the drill steel is held against rotation due to an abnormal resistance to rotation by the Work to lock the piston against rotation, and means controlled by said fluid distributing Valve for controlling the fluid to said combined pump and motor device to lock said rotary element against rotation during one piston stroke and for effecting free release of said rotary element during the opposite piston stroke.

i i. In a rock drill, a cylinder, a piston reciprocable therein for delivering impact blows to a drill steel and drill steel rotation means comprising an interlocking connection between the piston and the drill steel for transmitting the rotary motion of the piston to the steel, a rifle bar having a spiral groove interlocking connection with the piston for intermittently rotating the latter, locking means comprising a locking member connected to said rifle bar and movable upon angular movement of the rifle bar, said lochingmember held against axial movement with respect to the rifle bar, and means for supplying pressure fluid to said locking means to lock said locking member against movement to hold said rifle bar against angular movement during one stroke of the piston and for exhausting the fluid from said locking means to release said looking member to permit free angular movement of said rifle bar during the opposite piston stroke.

ELMER G. GARTIN.

CERTIFICATE OF CORRECTION. Patent Noe 2,100,52h. November 50, 1957.

of the above numbered patent requiring correction as'follows: Page 2, second column, line 2, for the word "causing" read permitting; and that the said Letters Patent should be read with thia correction therein that the same may conform to the record of the case in the Patent Office Signed and sealed this 1st day of February, A. D. 1958.,

Henry Van Arsdale, (Seal) Acting Commissioner of Patents; 

